On the other hand, Clarke et al.
conducted a meta-analysis of 8 large, randomized, placebocontrolled
trials of folic acid supplementation involving 37485
individuals at increased risk of cardiovascular disease but
did not find an increased risk of cancer: rate ratios (95%
confidence intervals) were 1.05 (0.98–1.13) for overall cancer
incidence, 1.00 (0.85–1.18) for cancer mortality, and 1.02
(0.97–1.08) for all-cause mortality